This invention relates generally to prosthetic devices and more particularly to a pump and valve assembly for use in combination with a penile implant device.
In order to remedy the effects of certain types of functional impotency, implants have been developed for surgical insertion in a penis in order to simulate a natural erection.
In that regard, various surgical implants and implant techniques entail implanting an inflatable bladder in each corpus cavernosum of the penis. A preferred type of penile implant which may be used in combination with the instant invention is disclosed and claimed in my copending U.S. patent application No. 313,114, filed on Oct. 20, 1981, and whose disclosure is incorporated by reference herein.
That implant basically comprises a pair of hollow, enclosed bladders, each having an access port to the interior thereof and formed of a membrane of thin, very flexible material, each of said bladders is capable of inflation by the introduction of a fluid (e.g., water) therein through its port. A respective one of the bladders is located in the passageway in each corpus cavernosum. When the bladders are filled with the fluid, they are inflated from their flaccid state to a third predetermined volume without causing the bladder membrane to undergo tension. The third predetermined volume is sufficiently great to cause the corpra cavernosa to expand so that the fiberous tissue envelope surrounding the corpora cavernosa encompasses the second predetermined volume, whereupon the fiberous tissue becomes tense and the penis becomes hard and erect.
In U.S. Pat. No. 3,954,102 (Buuck) there is disclosed a valve mechanism generally designed to accomplish the inflation and deflation of implanted bladers. The Buuck device comprises means for pumping fluid into the implanted bladders in order to obtain an erection, and valve means for releasing the fluid pressure in order to terminate the erection. With regard to the Buuck device, as well as penile implant systems in general, the resevoir containing the fluid is generally implanted within the patient's lower abdominal cavity. As a result, the patient's internal organs and abdominal wall combine to exert a fairly constant pressure of approximately one pound per square inch upon the walls of the reservoir. The valve system used in Buuck, as well as other prior art penile implant systems, generally fail to provide means for completely withdrawing fluid from the implanted bladders below the residual (e.g., one pound per square inch) level which remains within the bladders during such time that a flaccid state is desired. This residual pressure tends to result not in a flaccid penis but rather, results in a continuously semi-erect one. Moreover, additional fluid tends to build up within the bladders whenever the man coughs or exerts himself in a manner causing increased abdominal pressure to be exerted against the walls of the resevoir. In this regard, when the man coughs or tightens his abdominal muscles during exertion, the pressure on the reservoir increases, thus causing additional fluid to flow into and remain in the bladders. Thus, the bypass valve would have to be actuated periodically to allow the water to run back into the reservoir in order to reduce the pressure within the bladders to the residual level. For this reason, men utilizing prior art implant devices have frequently complained of discomfort associated with being unable to maintain a flaccid state.
Moreover, allowing the bladders, and thus the penis, to remain in a semi-erect state aside from being undesirable from an appearance standpoint can result in either the eventual rupturing of the bladders due to the maintained pressure or an eventual breakdown of the cells surrounding the corpora cavernosa.